One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10,14,17)(11,18,20,15)(12,21,13,16)(19,23,22,24)(25,26,30,34)(27,35,37,32)(28,31,39,36)(29,40,38,33)(3,4)(6,8)(9,11,14,20)(10,15,17,18)(12,19,13,22)(16,23,21,24)(25,27)(26,32)(28,33)(29,36)(30,37)(31,38)(34,35)(39,40)(1,3,5,4)(2,6,7,8)(25,28,31,34,30,39,36,26)(27,33,38,35,37,40,29,32)(9,12,14,13)(10,16,17,21)(11,19,20,22)(15,23,18,24)(25,29,30,38)(26,33,34,40)(27,36,37,31)(28,35,39,32)(1,4,5,3)(2,6,7,8)(9,13,14,12)(10,16,17,21)(11,19,20,22)(15,24,18,23)(27,37)(29,38)(32,35)(33,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.